Drop-off Method Research Articles

Detecting drug transfers via the drop-off method: A supervised model approach using AIS data

Maritime security is of tremendous importance in countering drug trafficking, particularly through sea-based routes. In this paper, we address the pressing need for effective detection methods by introducing a novel approach utilizing Automatic Identification System (AIS) data. Our focus lies on detecting the ‘drop-off’ method, a prevalent technique for contraband smuggling at sea. Unlike existing research, primarily employing unsupervised methods, we propose a supervised model specifically tailored to this illicit activity, with a particular emphasis on its application to fishing vessels.Our model significantly reduces the number of data points requiring classification by the observer by 70% , thereby enhancing the efficiency of the drop-off detection process. By employing a Long Short-Term Memory (LSTM) model, our approach demonstrates a change from traditional methods and offers advantages in capturing complex temporal patterns inherent in ‘drop-off’ activities. The rationale behind choosing LSTM lies in its ability to effectively model sequential data, which is essential for detecting drug traffic activities at sea where patterns are subtle and dynamic.Moreover, this model holds the potential for integration into real-time surveillance systems, thereby enhancing operational capabilities in detecting and preventing drug traffic. The generalizability of our model makes for considerable potential in enhancing maritime security efforts and providing assistance in countering drug traffic on a global scale. Importantly, our model outperforms both baseline models, underscoring its effectiveness and superiority in addressing the specific challenges posed by ‘drop-off’ detection. For more information and access to the code repository, please visit this link.

High-Throughput Bacteriophage Testing with Potency Determination: Validation of an Automated Pipetting and Phage Drop-Off Method.

The development of bacteriophages (phages) as active pharmaceutical ingredients for the treatment of patients is on its way and regulatory agencies are calling for reliable methods to assess phage potency. As the number of phage banks is increasing, so is the number of phages that need to be tested to identify therapeutic candidates. Currently, assessment of phage potency on a semi-solid medium to observe plaque-forming units is unavoidable and proves to be labor intensive when considering dozens of phage candidates. Here, we present a method based on automated pipetting and phage drop-off performed by a liquid-handling robot, allowing high-throughput testing and phage potency determination (based on phage titer and efficiency of plaquing). Ten phages were tested, individually and assembled into one cocktail, against 126 Escherichia coli strains. This automated method was compared to the reference one (manual assay) and validated in terms of reproducibility and concordance (ratio of results according to the Bland and Altman method: 0.99; Lin's concordance correlation coefficient: 0.86). We found that coefficients of variation were lower with automated pipetting (mean CV: 13.3% vs. 24.5%). Beyond speeding up the process of phage screening, this method could be used to standardize phage potency evaluation.

Evaluation of quantitative ultrasonic C-scan testing for refill friction stir spot welding joints based on time-frequency analysis

This paper focuses on a comparative study of different ultrasonic feature-based C-scan testing imaging methods for characterizing refill friction stir spot welding (RFSSW) joints, and accurately identifying and measuring the nugget boundary. The aim is to explore a suitable method for nugget characterization and automatic size analysis. The research indicates that the frequency-domain C-scan imaging method outperforms the time-domain C-scan imaging method in accurately characterizing the nugget. Furthermore, the C-scan imaging method based on the feature value of the base material zone (BMZ) echo signal performs better than the method based on the nugget echo signal. The tested nugget sizes obtained by using the –6 dB drop-off method to identify the boundaries in the C-scan images are generally larger than the metallographic measurement values. A novel method is proposed in this paper, using the difference in main frequency amplitude values between the BMZ and the nugget as the feature value for the C-scan testing image, and employing the Hough circle transformation for an automatic extraction of joint size. This method achieves improved nugget characterization and higher accuracy in size analysis.

The Impact of Service Quality on Business Commitment in Contract Manufacturing Services: An Exploratory Study of F&B Industry in Malaysia

Business environment is highly competitive for food & beverage(F&B)industry due to the low entry barrier. In order to improve their financial performances, F&B manufacturers opt to offer contract manufacturing services (CMS).There is a formal relationship established between the service provider and the buyer. However, the impact of service quality on retaining the business relationship particularly has not been empirically investigated. To fill this gap, this study explores the determinants of contract manufacturing service quality (CMSQ) and the interrelationship between CMSQ, customer satisfaction and loyalty of the F&B CMSs’ customers in Malaysia. Four focus group interviews (28 participants) were held in this study and they comprised 12 contract manufacturers and 16 business customers. Three new dimensions were discovered from the focus group interviews; product development capability, Halal certification and outcome quality in addition to the SERVQUAL dimensions. Relevantinformation via structured questionnaires were collected via online survey and drop-off method. 146 usable questionnaires were analysed using partial least squares. The results indicate that CMSQ consists of eight dimensions namely empathy, assurance, reliability, responsiveness, tangibles, outcome quality, Halal certification and product development capability. The Empathy dimension is the most important dimension influencing customers’ decision to stay with the contract manufacturers.CMSQ was found to have a small effect size on loyalty while customer satisfaction largely influenced loyalty. The result implies that CMSQ is a complement in the formation of customer loyalty while customer satisfaction is a significant predictor of behavioural intention.The findings also provide empirical evidence that the contextual specific service quality is essential particularly for contract manufacturing in F&B.

Intra-transfer of ownership factors and external transfer of ownership effects: evidence from the Gauteng enterprising community, South Africa

Purpose This paper aims to determine the perceptions of family-owned small enterprises on the external transfer of ownership and intra-transfer of ownership using empirical data. This permitted the research to successfully point out the factors that influence the internal transfer of ownership, and also, the effects of intra-transfer of ownership from a viewpoint of both family members and non-family members in small family-owned enterprises. Design/methodology/approach A quantitative research design was used to conduct this research, where primary data was gathered from a sample of 257 respondents using convenience and snowball sampling techniques. Data was collected through a survey instrument distributed via internet-based surveys (SurveyMonkey) and through a drop-off method. The gathered data was then captured, coded and analysed using Stata (version 15) statistical software. Findings The results divulged that intra or internal transfer of ownership is the preferred avenue compared to external transfer of ownership. This is because, when a family business is transferred to the next generation, it presents some benefits to family members working in the business and to the family at large. As a result, the empirical results show that factors that influence the internal transfer of ownership include: favouritism; security, stability and growth; a formal and structured succession plan. Business improvement and organisational change are then the effects of external transfer ownership. Although these effects make business sense, family members will advocate for internal transfer of ownership for them not to lose the benefits that come with the internal transfer of ownership. Research limitations/implications This paper adds to the current family business research in South Africa, thus reducing the shortage of such research. Moreover, the paper proposes further research that will provide tested, practical and detailed guidelines of survival in the next generation. Practical implications The paper empirically highlights the perils of selecting a successor based on favouritism rather than merit and possible consequences, thereby assisting those involved in family enterprise succession to make an informed decision when choosing a successor. Originality/value This research paper provides empirical evidence of the internal transfer of ownership factors and external transfer of ownership effects from a South African perspective.

Programmable set-up for electrochemical preparation of STM tips and ultra-sharp field emission cathodes

This paper describes a newly designed set-up which is intended for automated preparation both for STM tips and for ultra-sharp field emission cathodes made of polycrystalline and single crystal tungsten in laboratory conditions. The newly designed set-up incorporates electrochemical etching of a wire in the surface layer of an electrolyte and also the so called drop-off method which consists of two steps and requires more precise wire and current setting. Additionally, the method was extended for polycrystalline wires of tungsten using a special cut-off algorithm, which deals with variable etching speed for various crystallographic orientation of the current grain. Produced tips are examined using scanning low energy electron microscopy as for the surface and by the occurrence of electron field-emission as for the geometry based on the Fowler-Nordheim analysis. STM performance of the produced tip is discussed and examined as well.

Electrochemical Etching and Characterization of Sharp Field Emission Points for Electron Impact Ionization

A new variation of the drop-off method for fabricating field emission points by electrochemically etching tungsten rods in a NaOH solution is described. The results of studies in which the etching current and the molarity of the NaOH solution used in the etching process were varied are presented. The investigation of the geometry of the tips, by imaging them with a scanning electron microscope, and by operating them in field emission mode is also described. The field emission tips produced are intended to be used as an electron beam source for ion production via electron impact ionization of background gas or vapor in Penning trap mass spectrometry applications.

Confirmation of a non-synonymous SNP in PNPLA8 as a candidate causal mutation for Weaver syndrome in Brown Swiss cattle.

BackgroundBovine progressive degenerative myeloencephalopathy (Weaver syndrome) is a neurodegenerative disorder in Brown Swiss cattle that is characterized by progressive hind leg weakness and ataxia, while sensorium and spinal reflexes remain unaffected. Although the causal mutation has not been identified yet, an indirect genetic test based on six microsatellite markers and consequent exclusion of Weaver carriers from breeding have led to the complete absence of new cases for over two decades. Evaluation of disease status by imputation of 41 diagnostic single nucleotide polymorphisms (SNPs) and a common haplotype published in 2013 identified several suspected carriers in the current breeding population, which suggests a higher frequency of the Weaver allele than anticipated. In order to prevent the reemergence of the disease, this study aimed at mapping the gene that underlies Weaver syndrome and thus at providing the basis for direct genetic testing and monitoring of today’s Braunvieh/Brown Swiss herds.ResultsCombined linkage/linkage disequilibrium mapping on Bos taurus chromosome (BTA) 4 based on Illumina Bovine SNP50 genotypes of 43 Weaver-affected, 31 Weaver carrier and 86 Weaver-free animals resulted in a maximum likelihood ratio test statistic value at position 49,812,384 bp. The confidence interval (0.853 Mb) determined by the 2-LOD drop-off method was contained within a 1.72-Mb segment of extended homozygosity. Exploitation of whole-genome sequence data from two official Weaver carriers and 1145 other bulls that were sequenced in Run4 of the 1000 bull genomes project showed that only a non-synonymous SNP (rs800397662) within the PNPLA8 gene at position 49,878,773 bp was concordant with the Weaver carrier status. Targeted SNP genotyping confirmed this SNP as a candidate causal mutation for Weaver syndrome. Genotyping for the candidate causal mutation in a random sample of 2334 current Braunvieh animals suggested a frequency of the Weaver allele of 0.26 %.ConclusionsThrough combined use of exhaustive sequencing data and SNP genotyping results, we were able to provide evidence that supports the non-synonymous mutation at position 49,878,773 bp as the most likely causal mutation for Weaver syndrome. Further studies are needed to uncover the exact mechanisms that underlie this syndrome.Electronic supplementary materialThe online version of this article (doi:10.1186/s12711-016-0201-5) contains supplementary material, which is available to authorized users.

Viability of Musharakah as an Alternative Financing Mode for Small and Medium Enterprises: The Cases of Klang Valley and Selangor, Malaysia

Small and Medium Enterprises (SMEs) have been recognized as one of the most important component that contributes towards the economic growth of many countries around the world. Despite its importance, SMEs have limited access to external financing that is dominated by debt financing. They have difficulty in fulfilling debt requirements particularly in providing collateral, coping with high interest/ profit payment and adapting to credit rationing. Such limitations curb their growth and expansion.Therefore, there is a need to explore an alternative financing,which is more accessible by SMEs. Quantitative method is adopted in this study. Questionnaires were self administered using drop-off method, to a sample of 100 SMEs firms in Klang Valley and Selangor, Malaysia. The data were analyzed using Exploratory Factor Analysis. Musharakah is found to be s viable alternative financing mode for SMEs. Its three main features, namely (i) risks sharing (ii) profit and loss sharing and (iii) participation have immense potential of salvaging SMEs from their debt based challenges of access to financing, collateral, high interest. This study contributes towards a better understanding of the potential of Musharakah as a viable financing for SMEs. Hence, it provides foundation and direction in structuring Musharakah as an alternative financing mode for SMEs

Consumers’ perceptions of consumer rights in Jordan

Purpose – This paper aims to examine consumers’ attitudes toward marketing practices and consumer rights in Jordan, based on an empirical investigation of university students. The study refers to John Kennedy’s bill of four consumer rights: the Right to Safety, the Right to be Informed, the Right to Choose and the Right to be Heard. Design/methodology/approach – This paper depends on a convenience sample of 381 students, using a drop-off method, with a structured, self-administered questionnaire to measure consumer attitudes regarding the four basic consumer rights, as listed above, utilizing a five-point Likert scale measure. Findings – The overall findings show that the current consumers’ attitudes toward marketing practices related to protection of consumer rights is not highly favorable, indicating that more work will be needed for improvement, with more attention to consumers’ Right to be Heard. The study urged marketers and public policymakers in Jordan to reconsider the way consumer rights were bei...

Charge transport through chains of nanoparticles

We present transport measurements through nanoparticles as well as preparation techniques to contact short chains of nanoparticles. The nanoparticles are deposited onto a mica substrate in a dewetting process of hexane solution containing the nanoparticles. The measurements were done in a self-developed probing tip setup inside a SEM, where the probing tips were driven by piezoelectric motors. The platinum iridium tips were fabricated by anodic dissolving in a drop-off method which results in sharp tip diameters. With this setup it was possible to contact and measure the nanoparticles under vacuum conditions. The I– V characteristics show a power law behavior as expected for low dimensional cluster systems. Transport in the device is expected to be influenced by Coulomb blockade effects and disorder.

Green Marketing and the Concern over the Environment: Measuring Environmental Consciousness of Jordanian Consumers

SUMMARY The purpose of this article is to explore the attitudes of Jordanian consumers regarding both their current environmental consciousness and their willingness to adopt environmentally friendly consumption behavior. The article is based on an empirical investigation of consumer attitudes for a sample of 303 university students drawn from Jordanian universities, using a drop-off method. The article concludes that Jordanian consumers were, generally, concerned about the environment, as they demonstrated reasonably high levels of environmental consciousness relating to various environmental issues. However, this pro-environmental attitude was not sufficient to turn good intentions into actual buying actions, possibly due to several factors, such as loyalty to traditional products and weak credibility of “green” claims. The article stresses the need to link consumers' good intentions to actual buying behavior through a green marketing strategy, which focuses on the unique characteristics of green products and how they impact the environment, within the cultural context of the Jordanian consumer. Over time, we hope that these efforts can lead to a culture of green consumerism within a framework of environmental responsibility.

Mesoscale scanning probe tips with subnanometer rms roughness

Surface smoothness of probe tips is critical for applications, such as measuring surface tension of various liquids, oscillatory hydration forces, and interfacial shear strengths from friction experiments. In this study we establish conditions for fabricating tips with smooth surfaces by controlling the electrochemical polishing process throughout the tip evolution rather than following the current practice of producing tips by the drop-off method. Polishing is conducted under a constant voltage, with the wire immersed below the nominal air/electrolyte interface by no more than one-half of the wire diameter and stopping the etching at different current levels. This process provides a tip radius range of approximately 100 nm to 5 microm for a tungsten wire with a 0.2 mm diameter. Alternatively, the wire can be placed above the nominal air/electrolyte interface but within the meniscus until the current drops to zero. In this case, the tip radii range from 5 to 50 microm. In both cases, atomic force microscopy scans of these tips show that the surface rms roughness is about 0.3 nm.

Mapping QTLs on BTA6 affecting milk production traits in a Chinese Holstein population

A Chinese Holstein population with daughter design was analyzed using 14 microsatellites covering a map distance of 55.7 cM on chromosome 6 to fine map QTL for five milk production traits. 26 paternal half-sib families with 2356 daughters were involved. Two different approaches, linear regression approach and variance component approach, were employed, with a one-QTL model and two-QTL model fitted. With a one-QTL model, the linear regression approach revealed a QTL near BMS470 with effects on milk yield, fat yield, protein yield, and fat percentage, and another QTL near BMS2460 for protein percentage. The variance component approach confirmed the results of linear regression approach for the three yield traits, with the exception that the QTL for fat yield was mapped to a different position near BMS1242. The 95% confidence intervals resulted from linear regression, obtained by bootstrapping, were generally large, ranging from 31 to 53 cM, whereas the variance component approach revealed very small confidence intervals, calculated by LOD drop-off method, for the three yield traits, only 4–5 cM. With a two-QTL model, both approaches provided strong evidence for the existence of two QTLs for the three yield traits. Along with the QTLs identified in one-QTL model analyses, the linear regression approach revealed a second QTL near BP7 with effects on all the three yield traits, whereas the variance component approach located the second QTL near ILSS035, BMS470, and BP7 for the three traits, respectively.

Prediction of the confidence interval of quantitative trait Loci location.

In 1997, Darvasi and Soller presented empirical predictions of the confidence interval of quantitative trait loci (QTL) location for dense marker maps in experimental crosses. They showed from simulation results for backcross and F2 populations from inbred lines that the 95% confidence interval was a simple function of sample size and the effect of the QTL. In this study, we derive by theory simple equations that can be used to predict any confidence interval and show that for the 95% confidence interval, they are in good agreement with the empirical results given by Darvasi and Soller. A general form of the confidence interval is given that also applies to other population structures (e.g., collections of sib pairs). Furthermore, the expected shape of the likelihood-ratio-test around the true QTL location is derived, which is shown to be extremely leptokurtic. It is shown that this shape explains why confidence intervals from the Log of Odds (LOD) drop-off method and bootstrap results frequently differ for real data sets.

Field estimates of numbers of Ixodes scapularis (Acari:Ixodidae) larvae and nymphs per hectare successfully feeding on Peromyscus leucopus in Massachusetts.

The numbers of blacklegged tick, Ixodes scapularis Say, per hectare that engorged as larvae and nymphs on white-footed mice, Peromyscus leucopus (Rafinesque), were estimated at 3 sites in coastal Massachusetts. Estimates of numbers of engorged ticks dropping per day from trapped mice were multiplied by mark-recapture estimates of the density (numbers per hectare) of white-footed mice to estimate numbers of ticks engorging on mice per hectare. In 1991, estimates of seasonal totals per hectare of I. scapularis nymphs completing blood meals on P.leucopus ranged from 825 +/- 68 at Nonamesset to 6,654 +/- 770 at Menemsha. This absolute sampling method (the drop-off method) was compared with drag sampling for nymphal ticks. Per hectare estimation of engorgement rates overcomes a shortcoming associated with drag sampling because site-to-site comparisons can be made even where vegetation structure differs markedly among sites. The drop-off method may be used to quantify the contribution of any host to the engorged tick population, provided sufficient such hosts can be collected on a weekly basis.

Confidence Intervals in QTL Mapping by Bootstrapping

The determination of empirical confidence intervals for the location of quantitative trait loci (QTLs) was investigated using simulation. Empirical confidence intervals were calculated using a bootstrap resampling method for a backcross population derived from inbred lines. Sample sizes were either 200 or 500 individuals, and the QTL explained 1, 5, or 10% of the phenotypic variance. The method worked well in that the proportion of empirical confidence intervals that contained the simulated QTL was close to expectation. In general, the confidence intervals were slightly conservatively biased. Correlations between the test statistic and the width of the confidence interval were strongly negative, so that the stronger the evidence for a QTL segregating, the smaller the empirical confidence interval for its location. The size of the average confidence interval depended heavily on the population size and the effect of the QTL. Marker spacing had only a small effect on the average empirical confidence interval. The LOD drop-off method to calculate empirical support intervals gave confidence intervals that generally were too small, in particular if confidence intervals were calculated only for samples above a certain significance threshold. The bootstrap method is easy to implement and is useful in the analysis of experimental data.